The present invention relates to closure members for containers, bottles, and the like, and more particularly, to child-resistant push-and-turn closure members which are adapted for use on dispensing containers for potentially hazardous materials, such as pharmaceutical agents.
The present invention provides for the bi-modal operation of a closure for a container opening. The closure has a first mode intended for adult use, wherein the closure is readily opened, and a second child-resistant mode, wherein the closure is more difficult to open, especially by children. When engaged to an opening, at least a portion of the closure (a deflecting member) has a distal relationship to the opening wherein the closure is substantially non-removable from the opening, and a proximal relationship to the opening wherein the closure may be easily removed from the opening. In the first mode, the movement between the distal and the proximal relationships requires little or no downward force; while in the second mode, the force require to effect the movement is greatly increased (when the force required to move between the distal and proximal relationships in the first mode is non-zero, the force required in the second mode should be at least 25% greater than that required in the first mode, preferably 50% greater, and most preferably at least twice that of the first mode). The conversion between modes is accomplished by use of a bi-stable spring located in the closure, preferably on the top surface of the closure. The bi-stable spring is preferably an invertible disk, and in the first mode presents a convex surface to the user. Depressing this surface with sufficient force results in the inversion of the disk into a stable second mode wherein the disk is concave, and wherein the disk serves to directly or indirectly urge the closure (or part of the closure) into the distal relationship with the opening. The geometrical state of the disk serves as a visual and tactile cue as to the instant mode of the closure. Conversion may typically be accomplished with finger pressure alone, and without the need to disengage the closure from the bottle. The details of the internal structure of the closure may be altered to allow finger pressure to return the closure to the first mode (by accessing the back side of the closure), or the conversion to the second mode from the first mode may be made irreversible by preventing access to the bi-stable spring element from the back side of the closure.
It is an object of the present invention, therefore, to provide a container closure convertible from a first adult-use mode to a second child-resistant mode.
The closure has a bi-stable element in its upper surface with a first substantially convex stable orientation and a second substantially concave stable orientation. The first stable orientation has a first associated spring rate of the deflecting member, and the second stable orientation has a second associated spring rate of the deflecting member, wherein the second spring rate is greater than the first spring rate, and wherein the bi-stable element may be converted from the first to the second stable orientations by finger pressure.
A further object of the invention is to provide an intuitively natural means for converting the container closure from the first mode to the second mode.
Yet another object of one embodiment of the invention is to provide a reversibly convertible container closure, wherein the closure may be converted from an adult-use mode to a child-resistant mode and back again.
Yet another object of one embodiment of the invention is to provide an irreversibly convertible container closure.
Yet another object of one embodiment of the invention is to provide a bi-modal container closure that can be converted from an adult use mode to a child-resistant mode while closed.
Yet another object of one embodiment of the invention is to provide a container system selectable between adult and child-resistant modes, for storage of potentially hazardous materials, especially pharmaceutical agents.
And yet another object of the invention is to provide a convertible container closure having a tactile and/or visual indication of operational status.